This invention relates to packaging of semiconductor chips and, in particular, chips comprising light emitting displays.
At present, there is considerable activity in developing monolithic structures for GaP numeric and alpha-numeric displays. A typical numeric comprises seven electrodes in the form of bars arranged in a figure-eight configuration such that different combinations of electrodes will display all numerals from 0-9. These electrode segments require interconnections to auxiliary circuitry such as the necessary logic circuits and power supply. Present schemes for packaging such displays typically involve placing the display chip on a ceramic substrate including the auxiliary circuitry and making the necessary electrical connections by means of beam leads or wire bonding procedures. Beam lead bonding is a fairly complicated technology involving formation of several layers of metal. Wire bonding is simpler but usually requires many more individual wire bonds.
In addition to interconnect and bonding problems, a further problem associated with present schemes is the need for a colored filter over the display chip to provide contrast under ambient lighting conditions. This requires an additional piece part in the display package.
It is therefore a primary purpose of the invention to provide an inexpensive packaging scheme which reduces the number of piece parts and the number of handling steps required to interconnect the display chip with auxiliary circuitry. While the present disclosure is directed primarily to the formation of display packages, it should become clear that the inventive features may also be applied to bonding and mounting of other types of semiconductor chips.